1. Field of the Invention
This invention relates to a polymerization process, and more particularly, to non-aqueous, heterogeneous polymerization of a vinyl monomer in oil as a solvent.
2. Description of the Prior Art
J. Shih, in U.S. Pat. No. 5,015,708, described a non-aqueous, precipitation polymerization process for making N-vinyllactam terpolymers in which the polymerization step was carried out in an aliphatic hydrocarbon solvent such as heptane or hexane. The reaction product was a white powder of the terpolymer, however, with undesirable traces of heptane or hexane present therein.
S. Kopolow, in U.S. Pat. No. 5,130,121, disclosed an aqueous polymerization process for making a N-vinylpyrrolidone polymer encapsulating a silicone oil.
Accordingly, it is desired to provide a non-aqueous, heterogeneous polymerization process for making vinyl polymers using an oil solvent, whose presence both during the polymerization and in the reaction product is advantageous for commercial use of the vinyl polymer, particularly in cosmetic compositions.
These and other objects and features of the invention will be made apparent from the following description of the invention.